Recently, stricter environment protection regulations reflect a growing concern of people with contamination problems in general. Several states in the United States have enacted legislative measures to achieve better environmental protection, such as the Illinois Lawn Care Containment Act. The Act requires wash water containment areas to prevent spills and collect pesticide containing wash water from lawn care vehicles. The Act even specifies the minimum containment volume to be equal to or greater than the volume generated by a 6 inch rain storm. It also requires proper disposal or reuse of the wash liquid. However, not all lawncare operators can afford a permanent containment structure either because of the high cost or lack of available land space. Moreover, certain regulations prohibit or severely limit movement of a possible contaminated vehicle from a location of use to a permanent containment structure located elsewhere. Therefore, a portable wash containment liner system for lawncare vehicles, which is also relatively inexpensive, has become a much needed development.
Prior to this invention, there were a variety of known drainage collectors, disposable drip pans or mats, garage floor liners or foldable spill collectors. However, none of them can satisfy the requirements in the current environmental protection laws, such as the one in Illinois. U.S. Pat. No. 3,661,227 teaches a foldable drainage collection container to be used on the garage floor. It includes a floor sheet with flap extensions to wrap around resilient strips to form curbs of square cross-sections for the container. It cannot effectively prevent spills if the vehicle is driven over the curb while there is a large amount of water in the collector.
U.S. Pat. No. 4,671,024 to Schumacher shows a disposable drip pan of cylindrical curbs without corner sealing members. It cannot contain a relatively large volume of liquid, nor prevent liquid spills when the vehicle passes the curbs. U.S. Pat. No. 5,128,189 to Bartlett discloses a disposable mat with compressible ridge which cannot satisfy the requirements in the environmental protection Acts as well.
U.S. Pat. Nos. 2,996,150; 935,278 and 4,246,982 disclose, respectively, garage floor liners of non-portable structures. U.S. Pat. Nos. 5,316,175 and 5,090,588 teach, respectively, spill containers with high side walls, reinforced by vertical rigid bars at uniform intervals. Such wall structures are not supposed to stand upwardly very stably to hold the liquid of substantial height therein, but to retain a small amount of drainage within the area.